from machine import Pin, PWM
from time import sleep

buzzer = PWM(Pin(32,Pin.OUT))

def buzz(freq,masa):
    buzzer.duty(50) #on buzzer
    buzzer.freq(freq)
    sleep(masa)
    buzzer.duty(0) #off buzzer           

while (True):
    buzz(300,0.2) #300=freq, 0.2=masa bunyi
    buzz(350,0.2)
    buzz(400,0.2)
    buzz(1,0.2) #1=off bunyi, 0.2=masa off bunyi